What's so great about disc brakes?

[reuben]

This is becoming painful. I'm looking for a new (or used) road bike/frame. With rim brakes.

Disc brakes - can't stand 'em. Too fiddely (is that a word?). They rub, they're too loose, they're a pain to adjust. PITA. I've got some cheap ones, Sora I think, but I doubt that higher end ones are much better. ETA - I checked, and they're Spyre-C, similar to this (https://trpcycling.com/product/spyre/).

Rim brakes - just turn the adjusting screw. Done. No need to worry about adjusting something you can barely see to a tolerance of the width of a piece of onion skin paper.

You can try to talk me into disc brakes, but you'll have to work at it.

As discs take over the world, I've pretty much become a card carrying member of The Resistance. It's pretty easy to find good bikes/frames in your material of choice, but not so easy to find them with rim brake capability. In any design that's not freakin' nuts, like carved seatposts just to accommodate a 25mm road tire (I'm lookin' at you, Specialized).

Yes, I'm a bit of a curmudgeon. But this has gone too far.

Proprietary seatposts in funky shapes? Proprietary/integrated stems and handlebars? Are you kidding me?

Seems as though we have fewer options now for a given bike since some components are "locked in", aka proprietary. Not to mention our reduced ability to just walk in to the LBS and buy something that will fit whatever proprietary mess we've purchased.

But I digress.

What's so great about disc brakes? And why are manufacturers so unwilling to provide both options on most bikes?

[Clean39T]

It's not an adventure until something goes wrong. - Yvon C.

Disc brakes and proprietary parts are just increasing the odds of having a proper adventure each time you go out.. we should be thanking the industry for that, not chastising them.

:banana:

[David Tollefson]

Interesting that you're having so many problems with Spyre calipers. It's the only cable disc brake I'll use just because it's so easy to set up and maintain. And the only better performing discs will be hydraulic, which will have a whole new set of issues (bleeding, etc).

Don't get me wrong -- for road riding I still FAR prefer rim calipers (and sigle pivot at that), but once I leave pavement, or I'm riding in crappy weather, it's discs all day.

For the why: Better wet performance, no ground up rim dust to cause filthy hands when changing a flat, rims last forever (or until they're totally bunged by abusive riding)...

[tuscanyswe]

This is becoming painful. I'm looking for a new (or used) road bike/frame. With rim brakes.

Disc brakes - can't stand 'em. Too fiddely (is that a word?). They rub, they're too loose, they're a pain to adjust. PITA. I've got some cheap ones, Sora I think, but I doubt that higher end ones are much better. ETA - I checked, and they're Spyre-C, similar to this (https://trpcycling.com/product/spyre/).

Rim brakes - just turn the adjusting screw. Done. No need to worry about adjusting something you can barely see to a tolerance of the width of a piece of onion skin paper.

You can try to talk me into disc brakes, but you'll have to work at it.

As discs take over the world, I've pretty much become a card carrying member of The Resistance. It's pretty easy to find good bikes/frames in your material of choice, but not so easy to find them with rim brake capability. In any design that's not freakin' nuts, like carved seatposts just to accommodate a 25mm road tire (I'm lookin' at you, Specialized).

Yes, I'm a bit of a curmudgeon. But this has gone too far.

Proprietary seatposts in funky shapes? Proprietary/integrated stems and handlebars? Are you kidding me?

Seems as though we have fewer options now for a given bike since some components are "locked in", aka proprietary. Not to mention our reduced ability to just walk in to the LBS and buy something that will fit whatever proprietary mess we've purchased.

But I digress.

What's so great about disc brakes? And why are manufacturers so unwilling to provide both options on most bikes?

The easy answer is they will make more money getting ppl to venture into bikes with disc brakes. Everyone will need new everything as nothing fits with your parts bin of older bikes.

[kppolich]

Disc brakes, setup correctly don't do any of the things you listed above. Quality parts installed by a quality mechanic and maintained in a reasonable fashion over time will replace your rim caliper brakes.

Are they necessary? No
Do you have a choice? Yes
Are they better? Do you like stopping faster, ride a lot of downhills, or ride in the wet a lot?
Are they heavier? Marginally, for now.

[reuben]

It's not an adventure until something goes wrong. - Yvon C.

Disc brakes and proprietary parts are just increasing the odds of having a proper adventure each time you go out.. we should be thanking the industry for that, not chastising them.

:banana:

Touche.

[reuben]

The easy answer is they will make more money getting ppl to venture into bikes with disc brakes. Everyone will need new everything as nothing fits with your parts bin of older bikes.

Ah, for the good old days when seatposts were 26.0 or 27.2.

[reuben]

Interesting that you're having so many problems with Spyre calipers. It's the only cable disc brake I'll use just because it's so easy to set up and maintain. And the only better performing discs will be hydraulic, which will have a whole new set of issues (bleeding, etc).

Don't get me wrong -- for road riding I still FAR prefer rim calipers (and sigle pivot at that), but once I leave pavement, or I'm riding in crappy weather, it's discs all day.

For the why: Better wet performance, no ground up rim dust to cause filthy hands when changing a flat, rims last forever (or until they're totally bunged by abusive riding)...

I've been wondering if the Spyre-C are just cheap, and I should upgrade. I've thought about doing so, but would have no idea what to buy. Not sure that I like the idea of hydraulics (another point of failure), so I'd likely stick with cable if I did upgrade.

I'm also a rim caliper single pivot guy.

But I've ridden in the rain a lot over the years with rim brakes. And while I've crashed several times over the years, none were ever due to rim brakes.

Oh gawd, dirty hands? Really? After sweating for a few hours, swallowing a couple of bugs, and inhaling vehicle emissions, dirty hands are of no concern to me.

Less wear and tear on the rims is a valid point, though.

[weiwentg]

Disc brakes, setup correctly don't do any of the things you listed above. Quality parts installed by a quality mechanic and maintained in a reasonable fashion over time will replace your rim caliper brakes.

Are they necessary? No
Do you have a choice? Yes
Are they better? Do you like stopping faster, ride a lot of downhills, or ride in the wet a lot?
Are they heavier? Marginally, for now.

I might qualify that by saying hydraulic discs, set up correctly, don't have any of the issues described. Bleeding tends to be a once and done thing, unless you travel with the bike. I mention this because if Reuben has a full Sora group, then I don't think Sora has a hydraulic disc option at all. So he would have a third party cable disc brake. At the general price range implied by Sora, Claris, and Tiagra, bikes with discs would tend to have cable disc.

IMO, cheap cable disc brakes are clearly worse than rim brakes of the same cost. If I needed to go cable disc for some reason, I'd think about the cable actuated hydraulic style brakes like Yokozuna or Tektro Hy-Rd. And I'd make sure to get compressionless brake housing.

Other than that, this argument has been beaten to death many times already.

[sg8357]

It's not an adventure until something goes wrong. - Yvon C.

Disc brakes and proprietary parts are just increasing the odds of having a proper adventure each time you go out.. we should be thanking the industry for that, not chastising them.

:banana:

The Chouinard quote brings this to mind.

“I may say that this is the greatest factor: the way in which the expedition is equipped,
the way in which every difficulty is foreseen, and precautions taken for meeting or avoiding it.
Victory awaits him who has everything in order, luck, people call it
. Defeat is certain for him who has neglected to take the necessary precautions in time, this is called bad luck.”
― Roald Amundsen

[tuscanyswe]

I might qualify that by saying hydraulic discs, set up correctly, don't have any of the issues described. Bleeding tends to be a once and done thing, unless you travel with the bike. I mention this because if Reuben has a full Sora group, then I don't think Sora has a hydraulic disc option at all. So he would have a third party cable disc brake. At the general price range implied by Sora, Claris, and Tiagra, bikes with discs would tend to have cable disc.

IMO, cheap cable disc brakes are clearly worse than rim brakes of the same cost. If I needed to go cable disc for some reason, I'd think about the cable actuated hydraulic style brakes like Yokozuna or Tektro Hy-Rd. And I'd make sure to get compressionless brake housing.

Other than that, this argument has been beaten to death many times already.

I have never had a hydraulic disc brake lower than xt level (i think) and most if not all of them have started to rub or made sounds at some point so lets not pretend this is issues that are only related to low level of disc brake system because its not. My current DA on through axles rubs a little and the front stopping power has faded noticeably with half a season of use. Squeals every now and again as well. Installed by mechanic with 20+ years of experience.

[reuben]

I might qualify that by saying hydraulic discs, set up correctly, don't have any of the issues described. Bleeding tends to be a once and done thing, unless you travel with the bike. I mention this because if Reuben has a full Sora group, then I don't think Sora has a hydraulic disc option at all. So he would have a third party cable disc brake. At the general price range implied by Sora, Claris, and Tiagra, bikes with discs would tend to have cable disc.

IMO, cheap cable disc brakes are clearly worse than rim brakes of the same cost. If I needed to go cable disc for some reason, I'd think about the cable actuated hydraulic style brakes like Yokozuna or Tektro Hy-Rd. And I'd make sure to get compressionless brake housing.

Other than that, this argument has been beaten to death many times already.

Mostly Sora (which seems to be 3 levels down from the Ultegra-like performance I'm used to), with the obvious exception of the TRP Spyre-C brakes, which are cable, not hydraulic.

When I bought it a few years ago I knew I wasn't buying a great bike, but it was fine for the original intent. Now that I'm riding it more I'm less pleased. So, yeah, I'm looking at N+1...

[weiwentg]

...

Proprietary seatposts in funky shapes? Proprietary/integrated stems and handlebars? Are you kidding me?

Seems as though we have fewer options now for a given bike since some components are "locked in", aka proprietary. Not to mention our reduced ability to just walk in to the LBS and buy something that will fit whatever proprietary mess we've purchased.
...

A fair point, but right now, it looks like the big brands are reserving the integrated and proprietary front ends for the top tier bikes, e.g. the Emonda SLR. The Emonda SL looks like the same general frameset, lower grade of carbon, and standard bars and stem. That frame uses a seatmast, hence proprietary. But the Cervelo Caledonia takes standard bars, stem, and a 27.2 post, whereas the Caledonia-5 has proprietary bars, stem, and post. So, there are still options from the big manufacturers.

[colker]

Disc brakes are excellent for endless debate on cycling forums

[prototoast]

I like not hearing the sound of my rims being destroyed on wet or dirty descents.

[cgates66]

Hydraulic disc brakes are "set it and forget it" things, and they run quietly. Cable-pull disc brakes are probably the worst of both worlds (fiddly cable, weight and complexity of discs).

The main advantage of disc brakes is that you can run wide, light rims that are still strong so you can run wider tires. I don't know if there are other types of brakes that may also help with this, but probably so. A secondary advantage is that all rim-brake wheels eventually wear out at the brake track, although this can take quite some time. And rim heating is avoided, which is probably especially helpful if you run tubeless at higher pressures and brake a lot. I'm not sure about the rest of it.

I personally don't believe disc brakes confer a meaningful performance advantage with road bikes, but they feel somewhat nicer and I run wider tires and rims so I like them / don't have a choice. They are heavier and more complex. This is like most cycling tech. Some of it looks cool, some of it is theoretically good, but most of it is collectively irrelevant. *Guilty of 60mm carbon wheels, fancy aero handlebars, disc brakes etc.

If you are happy with 25c tires and rims out to about 27mm, there is no technical reason to run discs that I can see in terms of what's available on the market. If you want 30mm+ rims and 28c tires, you don't have a choice today.

[tomato coupe]

Disc brakes - can't stand 'em... I've got some cheap ones, Sora I think, but I doubt that higher end ones are much better.
Yep, perfectly rational conclusion. Same as with cars -- why would a Porsche 911 be any better than a VW bug?

[AngryScientist]

no kidding eh?

i really had a fight with a set last week. i let 'em go too long though.

https://forums.thepaceline.net/attachment.php?attachmentid=1698005528&stc=1&d=1596491243

[David Tollefson]

And I'd make sure to get compressionless brake housing.

This ^^ excellent point needs to be re-emphasized.

[tuxbailey]

no kidding eh?

i really had a fight with a set last week. i let 'em go too long though.

https://forums.thepaceline.net/attachment.php?attachmentid=1698005528&stc=1&d=1596491243

Yikes. Did you soak the whole thing with PB Blaster for an hour before taking a sledgehammer to it?

Also, smear some of that Ti anti-seize on the hub before putting on new ones.

[reuben]

no kidding eh?

i really had a fight with a set last week. i let 'em go too long though.

https://forums.thepaceline.net/attachment.php?attachmentid=1698005528&stc=1&d=1596491243

You should check your tires while you're at it.

https://forums.thepaceline.net/showthread.php?t=256728

[mhespenheide]

If you are happy with 25c tires and rims out to about 27mm, there is no technical reason to run discs that I can see in terms of what's available on the market. If you want 30mm+ rims and 28c tires, you don't have a choice today.

!

Cantilever brakes, center pull brakes, and mid-reach calipers would like to talk with you.

[reuben]

I should add a particular point which I forget in my OP.

So, off the disc/rim debate for the moment, and into my particular case.

The rear brake seems to be adjustable from both sides - there's a 3mm allen socket on both sides. However, the interior one, next to the hub, just spins in both directions and does nothing. Thinking that it was somehow broken, I took it to the LBS where I bought the bike about 3 years ago.

The mechanic seemed to think it was OK. He didn't seem overly confident in that assessment, but I couldn't tell if it was because he was unfamiliar with the brakes (not likely) or honestly struggling to understand my concern.

He said that normally only the outside one is adjustable, but again, he didn't seem confident that that was the case with the Spyre-C brakes I have.

He wasn't concerned about the interior socket spinning with no resistance.

[David Tollefson]

I should add a particular point which I forget in my OP.

So, off the disc/rim debate for the moment, and into my particular case.

The rear brake seems to be adjustable from both sides - there's a 3mm allen socket on both sides. However, the interior one, next to the hub, just spins in both directions and does nothing. Thinking that it was somehow broken, I took it to the LBS where I bought the bike about 3 years ago.

The mechanic seemed to think it was OK. He didn't seem overly confident in that assessment, but I couldn't tell if it was because he was unfamiliar with the brakes (not likely) or honestly struggling to understand my concern.

He said that normally only the outside one is adjustable, but again, he didn't seem confident that that was the case with the Spyre-C brakes I have.

He wasn't concerned about the interior socket spinning with no resistance.

Time for a new mechanic.

[reuben]

Yep, perfectly rational conclusion. Same as with cars -- why would a Porsche 911 be any better than a VW bug?

The VW bug doesn't have rim brakes.

But in any case, having a lesser vehicle might help prevent people from doing stupid things.

https://forums.thepaceline.net/showthread.php?t=256566

[slowpoke]

The rear brake seems to be adjustable from both sides - there's a 3mm allen socket on both sides. However, the interior one, next to the hub, just spins in both directions and does nothing. Thinking that it was somehow broken, I took it to the LBS where I bought the bike about 3 years ago.

[...]

He wasn't concerned about the interior socket spinning with no resistance.

reuben, Spyres have a known issue with the pad adjustment screw (the 3mm hex socket). I've posted about it here before:

https://forums.thepaceline.net/showthread.php?p=2738529#post2738529

Most folks here seem to have not experienced it, but I had. The design of Spyres' pad adjuster is trash (just put more threadlocker on it...). If you're going to stick with cable-actuated discs, go with Paul Klampers, otherwise revert to 622/584mm-sized disc brakes with rubber pads. ;)

[unterhausen]

don't buy a disc brake bike if you don't want one. If enough people do that, we might be able to buy decent rims for a couple of years longer

[OtayBW]

I have absolutely no dog in this fight, but wouldn't this have as much to do with what type of riding you do as personal (mechanical) preference?

[reuben]

reuben, Spyres have a known issue with the pad adjustment screw (the 3mm hex socket). I've posted about it here before:

https://forums.thepaceline.net/showthread.php?p=2738529#post2738529

Most folks here seem to have not experienced it, but I had. The design of Spyres' pad adjuster is trash (just put more threadlocker on it...). If you're going to stick with cable-actuated discs, go with Paul Klampers, otherwise revert to 622/584mm-sized disc brakes with rubber pads. ;)

Ah ha! This posty by wallymann mentions something that has been lurking in the back of my brain.

QR wheels always-always-always recenter slightly off when reinstalled (infinitesimally small, but noticeable with discs). so the multi-step adjustment procedure becomes a PITA when required so frequently.

I've thought about replacing the Spyre with something better, and learning how to deal with disc brakes along the way. It's certainly not something I look forward to, but perhaps something I need to knuckle down and do anyway.

Is the collective opinion of the Paceline Borg that Klampers is a good way to go? I guess I need to take some measurements to figure out what will fit - bolt distances, disc diameter, etc. And how to adjust the cables. Oh joy.

The rear Spyre-C has two mounting screws, about 75mm apart, which seems to be the "post mount" version, at least for the rear (sorry - as you may have noticed, I know nothing about bicycle disc brakes). The rotors read 140-14. 140 seems to be the diameter. I don't know about the 14, but I'll figure it out.

[reuben]

I have absolutely no dog in this fight, but wouldn't this have as much to do with what type of riding you do as personal (mechanical) preference?

Beats me. I'm a 100% roadie on decent roads, and I'll ride in the rain.

[reuben]

don't buy a disc brake bike if you don't want one. If enough people do that, we might be able to buy decent rims for a couple of years longer

Truth!

[OtayBW]

Beats me. I'm a 100% roadie on decent roads, and I'll ride in the rain.Me, too. That's why I have no dog in this fight! [emoji16]

Sent from my SM-G935V using Tapatalk

[Red Tornado]

I should add a particular point which I forget in my OP.

So, off the disc/rim debate for the moment, and into my particular case.

The rear brake seems to be adjustable from both sides - there's a 3mm allen socket on both sides. However, the interior one, next to the hub, just spins in both directions and does nothing. Thinking that it was somehow broken, I took it to the LBS where I bought the bike about 3 years ago.

The mechanic seemed to think it was OK. He didn't seem overly confident in that assessment, but I couldn't tell if it was because he was unfamiliar with the brakes (not likely) or honestly struggling to understand my concern.

He said that normally only the outside one is adjustable, but again, he didn't seem confident that that was the case with the Spyre-C brakes I have.

He wasn't concerned about the interior socket spinning with no resistance.

Time for a new mechanic.

Amen to that. I use TRP Spyke cable discs on one of my MTB's. The ability to adjust the pad position from both sides of the caliper was one of the main reasons I bought them. I have heard of the inboard side sometimes not working after a while, though, and sounds like you might be in that group.
The mechanic is correct for other brands, but not these.

[Bici-Sonora]

!

Cantilever brakes, center pull brakes, and mid-reach calipers would like to talk with you.

This ^^^. I currently run 32, 35, 38, and 43mm tires on rim brake bikes.

[Bob Ross]

I might qualify that by saying hydraulic discs, set up correctly, don't have any of the issues described. Bleeding tends to be a once and done thing, unless you travel with the bike

...or unless you have a lemon? I'll admit my first-hand experience with hydraulic brakes is limited to a sample set of 1, but if the crap my wife has had to deal with over the past two years is any indication of what hydraulic brakes entail, Imma remain a luddite and stick w/ mechanical, thank you very much.

I probably documented all the headaches in another thread here or across the hall, so I'll just summarize: In the first ~6 months of owning the bike -- built by an extremely well-respected craftsman who earns accolades in this forum regularly, and built out of high end components (Ultegra Di2) -- she had to
- get the brakes bled five times
- get one brake lever replaced under warranty
- get all the hoses & fittings replaced not under warranty

And then just this past week, 18 months after all ^^^that nonsense, the problem started recurring. Basically she loses all pressure in the system, the levers suddenly can be pulled all the way back to the bars, and her braking effectiveness declines by an order of magnitude. "Uh, there must be air trapped in the system" observed one mechanic...in between the two times he bled the system over the same weekend.


...which is not to say I prefer non-hydro discs: From my other sample size of 1 (my own bike with mechanical TRP brakes) I've had to deal with non-centering pads and squeaky rotors for almost as long as I've owned the bike.

The one advantage I can see for disc brakes over rim brakes is there's no chance for a blowout due to overheating the rim when braking on a long mountain descent. Which has happened to me exactly once in the last ~90,000 miles of obsessive recreational road cycling. I guess I like that they seem less finicky in wet weather. Or at least less dirty.

OP, we can hang. :::beer:::

[Mark McM]

don't buy a disc brake bike if you don't want one. If enough people do that, we might be able to buy decent rims for a couple of years longer

I'm pretty sure that the bike companies have reasoned out that bicycle buyers can be divided into 3 groups:

1. Those who will only buy a bike if it has disc brakes
2. Those who will only but a bike if it has rim brakes
3. Those who don't have a strong preference for brake types, as long as the bike meets their other criteria.

Even if most people fit in group 3, as long the size of group 1 is significantly larger than size of group 2, then the marginal increase in sales by making rim brake bikes doesn't just the cost of designing, manufacturing and stocking rim brake bikes.

Although many claim that those who prefer rim brakes will always have that option, the economies of mass manufacturing say otherwise.

A similar thing is happening with tubular tires - fewer and fewer new wheels are available in a tubular tire version, and it won't be too long before tubular wheels are just not available in any meaningful selection.

[Bici-Sonora]

Here’s a more interesting question IMO: what will be the last year a world stage is won on rim brakes? 2021, 2025, 2030? If, as some are suggesting, the supply of high end rim brake rims and wheels is gonna dry up, it seems to me that every year that pro riders win stages on rim brakes ensures that there will still be a supply of top level wheels around for awhile longer. https://uploads.tapatalk-cdn.com/20200817/48ba0b3b52a455ae1c93b69a478bca62.jpg


Sent from my iPhone using Tapatalk

[tomato coupe]

Here's a nice article by James Huang about why Jumbo Visma uses rim brakes:
https://cyclingtips.com/2020/08/wout-van-aert-wins-on-rim-brakes-so-what/https://uploads.tapatalk-cdn.com/20200817/48ba0b3b52a455ae1c93b69a478bca62.jpg

[Waldo62]

They're ugly, heavy, create dirty air, and squeal when not set up just right. Other than stopping really well in dry and wet, there's nothing to recommend them. I hate them.

[tomato coupe]

They're ugly, heavy, create dirty air, and squeal when not set up just right ... I hate them.
Are you describing disc brakes, or the people who complain about them?

[RWL2222]

~90,000 miles of obsessive recreational road cycling :::beer:::

Wow that's impressive

[Bici-Sonora]

The James Huang article has some good explanations about why a team would choose rim brakes over discs for certain race stages.

IMO, as long as rim brake bikes and wheels are lighter, easier/faster to change wheels, and less finicky in general, it seems to me that the only reason that pro teams would not use them in some race situations is: sponsor pressure.

My point was that Jumbo Visma and other pro tour teams winning stages on rim brakes keeps rim brakes relevant and makes it harder for manufacturers to write off the technology as old and obsolete. It keeps the supply of good rim stuff around a little longer. I cheer on every rim brake #victory for that reason.

None of you disc lovers want to hazard a guess about the last year a world tour stage will be won on rim brakes? My guess is 2027--by then maybe there will be an quick disc "quick" release.

[benb]

How much of a mechanic are you?

Your post seems to be from inexperience with different brakes.

If you were comparing a cheap rim brake that was a V-brake or Canti against a full hydraulic setup on a MTB you'd come to a 100% opposite conclusion.

The Spyre has little in common with a really good disc brake setup just like a $10 Tektro CR720 has very little in common with a Dura-Ace rim brake.

A good hydraulic caliper doesn't even have any side to side adjustments.. the hydraulics keep the pad centered and you don't adjust anything once the brake is setup till the pads are worn.

For most of us once we've got a good disc setup most of the negatives (a few grams, neutral race support, time to change a tire in a race, etc..) don't really matter.

Personally I've never really had any trouble at all removing/replacing the wheels on my bike with discs. Sometimes you work on a rim brake bike that's harder IMO if the bike has decent size tires & the rim brake in question doesn't open up very far.

I have V-brakes, Side pull rim brakes, and a bike with full hydraulic discs. The V-brakes are by far the slowest to remove and replace a tire... first because of the need to unhook the straddle cable, and then cause it has semi-horizontal dropouts, and then sometimes the cable gets hung up when re-attaching it. The MTB with discs might be the fastest.. all you have to do is watch the disc as you put the wheel back in when and make sure the disc gets in the slot between the pads. It's not rocket science. But there's no adjusters on the calipers that have to be opened and no cables to disconnect.

[Bici-Sonora]

I should say that I don't have a dog in this fight: but I do like rooting for the underdog:) I have two disc bikes and numerous rim brake bikes all of which I love riding. Now building up disc bikes--much more of a PITA (and less fun) in my experience than working on rim brakes. To each their own.

[Jaybee]

At least disc brakes give us something to talk about.

I don't really care what anyone else rides, but I do find the conflation of the "what the pros are riding and why" argument with the "what should I be riding" argument to be... weird.

[benb]

The what the Pros are riding aspect is almost meaningless IMO.

The James Huang article is grasping at every straw he can to try and come up with a reason bike selection or brake selection or wheel selection is anything less than of a vanishingly marginal factor in Wout van Aert winning races.

The Bianchi frame is so inferior in weight/aero to the point that Wout couldn't win on it if he also had to have the penalty in weight/aero of discs?

More like he just made the right moves, is in great shape, and the bike and either type of brake was 100% sufficient for him to win with.

I'd probably be ticked off if I won a race and some guy was writing an article trying to say the win was cause of equipment instead of the guy on the bike.

If you know what you're doing on a dry descent both types of brakes are way more than sufficient.

These guys who write about bikes for a living are in the business of selling new bike equipment so it's their job to try and make the equipment seem more important than it is when someone wins a race.

Every pro has a top notch bike.. unless the bike breaks or the tires are flatting it's probably never making much of a difference.

[charliedid]

Ride bikes not brakes.

[Bob Ross]

Wow that's impressive

That I rode that many miles, or that I only had one overheating-rim-related blowout in all those miles?

If the former...to be fair, that's over the course of 15 or 16 years.

If the latter...here's my secret on long mountain descents: I hardly ever touch the brakes.

[robt57]

I did have heat induced rim temp while descending make my rim tape glue? soften and I must have had a torque on the tube inside the tire. It spun the tape off the spoke holes and the tube popped into the rim @ speed. Tire stayed on the beads and I stopped straight and no car around etc etc.

If I was descending long stuff with switchbacks I'd prefer the discs hands down. Clydes like me make some good heat on rim brakes slowing our girth.

That said, I actually prefer rim brakes on road bikes. Plus tubeless tires can make the heat thing lesser maybe?

But I say it over and over, 28" disc stops VG.

[RWL2222]

^^^the total (not the absence of downhill blowouts):that's a lot of year-in-year-out consistency.

[robt57]

...here's my secret on long mountain descents: I hardly ever touch the brakes.

No switchbacks on your mtn descents then ?

[Bob Ross]

^^^the total (not the absence of downhill blowouts):that's a lot of year-in-year-out consistency.

Thanks, I try. I've managed to clock between 5,000 and 8,000 miles annually since I first got into this sport with an almost disturbing uniformity: My week-to-week average year round is almost always within ~50 miles.


No switchbacks on your mtn descents then ?

No fear of switchbacks. I take the opposite approach of the Vote Early, Vote Often crew: Brake Late, If Ever.

I know, one of these days it's gonna bite me in the ass...

[rallizes]

That I rode that many miles, or that I only had one overheating-rim-related blowout in all those miles?

If the former...to be fair, that's over the course of 15 or 16 years.

If the latter...here's my secret on long mountain descents: I hardly ever touch the brakes.

are these long mountain descents near NYC or elsewhere?

[jtakeda]

Has no one mentioned that disc brakes allow you to run different diameter wheels? Being able to ride big 650b and moderate 700c is a huge plus for me and that’s why I went disc for my gravel bike

[19wisconsin64]

So, if you are going downhill at 40 plus miles an hour, and up ahead there is a stopped truck, and nowhere for you and your bike to go other than to stop quickly or plow into the truck's back end.....which brakes would you rather be on? It's that simple. If you are going at speeds below 20 miles an hour all the time, I can't see the benefit other than in the rain, but now having ridden a disc brake equipped bike...... I'm a convert. It's not marketing hype, it's engineering.

Just wish they had rounded smooth edges on the discs.

[tomato coupe]

I'd probably be ticked off if I won a race and some guy was writing an article trying to say the win was cause of equipment instead of the guy on the bike.

First paragraph:

"... I’ll agree that it’s the rider who wins a race, not the bike."

Last paragraph:

"... it wasn’t the rim brakes that won Strade Bianche and Milan-San Remo. Wout did that."

[reuben]

I don't really care what anyone else rides, but I do find the conflation of the "what the pros are riding and why" argument with the "what should I be riding" argument to be... weird.

Yeah, just to be clear, I'm not a pro riding for a top flight team in Europe. I should have stated so in my opening post. Sorry for the confusion.

[chunkylover53]

As primarily a mountain biker who rides a bit of road (and more gravel), I always find these discussions about disc brakes and tubeless tires etc interesting because folks here are having arguments/discussions that mountain bikers got over much earlier. When disc brakes first starting coming on mountain bikes the reaction was “not needed, finicky, heavy etc.” Now show me a mountain bike that doesn’t have them - they’re bombproof and better (I’m not comparing the braking needs of a mtb to a road bike). Same with tubeless tires - I always read here how it’s not needed, makes a mess, impossible to set up etc. Yeah, maybe before there were tubeless specific tires, and before you try setting it up a few times. But’s now it’s simple and better (for mtb and gravel, and I’m convinced for road but I won’t die on that hill lol).

As I say, just an observation. There’s something about the stereotype of the roadie vs. Mountain biker in there :). Do I think disc brakes are better for road? I do, especially if you ride in an area where a lot is asked of your brakes. But they certainly aren’t needed (especially to the same degree as in mtbing).

[tomato coupe]

As primarily a mountain biker who rides a bit of road (and more gravel), I always find these discussions about disc brakes and tubeless tires etc interesting because folks here are having arguments/discussions that mountain bikers got over much earlier. When disc brakes first starting coming on mountain bikes the reaction was “not needed, finicky, heavy etc.” Now show me a mountain bike that doesn’t have them - they’re bombproof and better (I’m not comparing the braking needs of a mtb to a road bike). Same with tubeless tires - I always read here how it’s not needed, makes a mess, impossible to set up etc. Yeah, maybe before there were tubeless specific tires, and before you try setting it up a few times. But’s now it’s simple and better (for mtb and gravel, and I’m convinced for road but I won’t die on that hill lol).

As I say, just an observation. There’s something about the stereotype of the roadie vs. Mountain biker in there :). Do I think disc brakes are better for road? I do, especially if you ride in an area where a lot is asked of your brakes. But they certainly aren’t needed (especially to the same degree as in mtbing).

I'd bet that the average age of people who post on this forum is quite a bit higher than the average mountain biker, and they are waaaaay less receptive to changing technology than the average mountain biker.

[chunkylover53]

You said it, not me, lol

I'd bet that the average age of people who post on this forum is quite a bit higher than the average mountain biker, and they are waaaaay less receptive to changing technology than the average mountain biker.

[Bob Ross]

are these long mountain descents near NYC or elsewhere?

Most of the genuinely long mountain descents I've done were in the Colorado Rockies, Park City UT, the "California Alps" (aka, the Markleeville Death Ride), Tucson AZ, or Sardegna. Around NYC the longest curvy mountain descent I encounter with any regularity is ~1 or 2 miles, and I'll just bomb that with impunity.

[Mark McM]

How much of a mechanic are you?

Your post seems to be from inexperience with different brakes.

If you were comparing a cheap rim brake that was a V-brake or Canti against a full hydraulic setup on a MTB you'd come to a 100% opposite conclusion.

The Spyre has little in common with a really good disc brake setup just like a $10 Tektro CR720 has very little in common with a Dura-Ace rim brake.

A good hydraulic caliper doesn't even have any side to side adjustments.. the hydraulics keep the pad centered and you don't adjust anything once the brake is setup till the pads are worn.

For most of us once we've got a good disc setup most of the negatives (a few grams, neutral race support, time to change a tire in a race, etc..) don't really matter.

Personally I've never really had any trouble at all removing/replacing the wheels on my bike with discs. Sometimes you work on a rim brake bike that's harder IMO if the bike has decent size tires & the rim brake in question doesn't open up very far.

I have V-brakes, Side pull rim brakes, and a bike with full hydraulic discs. The V-brakes are by far the slowest to remove and replace a tire... first because of the need to unhook the straddle cable, and then cause it has semi-horizontal dropouts, and then sometimes the cable gets hung up when re-attaching it. The MTB with discs might be the fastest.. all you have to do is watch the disc as you put the wheel back in when and make sure the disc gets in the slot between the pads. It's not rocket science. But there's no adjusters on the calipers that have to be opened and no cables to disconnect.


I'm going to guess that you don't have multiple wheel sets for your disc brake bike, because you didn't mention one of the steps when setting up the brake - shimming the rotors. Disc brakes have very little pad clearance, which means there is a tight tolerance for variation in rotor offsets. There can be variations in rotor offset between different wheels/hubs, so to make wheels truly interchangeable the rotors often have to be shimmed. This is one of the reasons that pro racers often change bikes instead of wheels - while it is true that disc brake wheel change is only a little slower than for rim brakes, there's a good chance that the replacement wheel may have a different rotor offset (especially if the wheel is from neutral service), which can result in pad rub. While this is of vital concern for racers, it is also a bit of a hassle for anyone with multiple wheels, or who borrows wheels.

[Mark McM]

As primarily a mountain biker who rides a bit of road (and more gravel), I always find these discussions about disc brakes and tubeless tires etc interesting because folks here are having arguments/discussions that mountain bikers got over much earlier. When disc brakes first starting coming on mountain bikes the reaction was “not needed, finicky, heavy etc.” Now show me a mountain bike that doesn’t have them - they’re bombproof and better (I’m not comparing the braking needs of a mtb to a road bike). Same with tubeless tires - I always read here how it’s not needed, makes a mess, impossible to set up etc. Yeah, maybe before there were tubeless specific tires, and before you try setting it up a few times. But’s now it’s simple and better (for mtb and gravel, and I’m convinced for road but I won’t die on that hill lol).

As I say, just an observation. There’s something about the stereotype of the roadie vs. Mountain biker in there :). Do I think disc brakes are better for road? I do, especially if you ride in an area where a lot is asked of your brakes. But they certainly aren’t needed (especially to the same degree as in mtbing).

What works best on one type of bike doesn't necessarily work best on other types of bikes. Do you also find it strange that road bikes don't have hydraulically damped suspensions, or dropper posts, or straight handlebars, or knobby tires? MTbs have them why not road bikes?

One big reason that MTBs have almost universally adopted disc brakes, is because rim brakes just don't work well on suspension forks or swingarms. Another reason is that MTBs are often used in mucky, gritty condition, which can grind down rims when rim brakes are used. Rim failures due to grinding down brake tracks was very common on MTBs when rim brakes were common, but is much less common on road bikes. I know several people who got disc brakes on the MTB simply to avoid needing to replace their rims more than once a year.

[Mark McM]

No switchbacks on your mtn descents then ?

Like everyone else, I've heard lots of stories about overheating rims/brakes on steep descents. Then I did an experiment. Mt. Ascutney in Vermont is a 3 1/2 mile/2400 foot descent at an average grade of 12%. The road is narrow and has many switchbacks, and it is open to traffic and in a dense forrest so you can't see around corners. Needless to say, you have to use your brakes quite a bit. I descended this mountain a few times, using as much braking as necessary to remain safe, and at the bottom I immediately braked to a halt and grabbed front and rear rims to see how hot they were. They were definitely warm, but I wouldn't all them "hot". Not hot enough to worry about, anyway. I also hadn't noticed any fading of the brakes on the way down.

Maybe I'm fortunate that I'm not very heavy (I run around 150 lb), and maybe I have good descending and braking technique, but I no longer worry too much about overheating rim brakes.

[chunkylover53]

What works best on one type of bike doesn't necessarily work best on other types of bikes. Do you also find it strange that road bikes don't have hydraulically damped suspensions, or dropper posts, or straight handlebars, or knobby tires? MTbs have them why not road bikes?

One big reason that MTBs have almost universally adopted disc brakes, is because rim brakes just don't work well on suspension forks or swingarms. Another reason is that MTBs are often used in mucky, gritty condition, which can grind down rims when rim brakes are used. Rim failures due to grinding down brake tracks was very common on MTBs when rim brakes were common, but is much less common on road bikes. I know several people who got disc brakes on the MTB simply to avoid needing to replace their rims more than once a year.

You’re missing my point. I explicitly say that you can’t compare the two. The observation was about the attitudes of mountain bikers and roadies.

[Mark McM]

So, if you are going downhill at 40 plus miles an hour, and up ahead there is a stopped truck, and nowhere for you and your bike to go other than to stop quickly or plow into the truck's back end.....which brakes would you rather be on? It's that simple. If you are going at speeds below 20 miles an hour all the time, I can't see the benefit other than in the rain, but now having ridden a disc brake equipped bike...... I'm a convert. It's not marketing hype, it's engineering.

Just wish they had rounded smooth edges on the discs.

Hey, nice fear mongering! Most tests of rim vs. disc brakes find that at least in dry conditions (and with testers who know how to brake), there is little distance in stopping distance between rim and disc brakes. That's because the limit of braking isn't how much braking friction/torque that can be applied to the wheels, its the rear wheel lift off point. Even GCN, which likes to hype the latest and greatest, strained to find any difference in stopping distance between rim and disc brakes.

[nmrt]

Bringing multiple wheelsets can complicate analysis and tip favor to the rim brake frame. Just like riding larger size tires tip the favor to disc brake bikes.

really, no, i mean really, people should ride whatever they want to ride for any reason or despite the lack of it.

i mean, i am a manual transmission curmudgeon who would prefer a 6-speed manual transmission even to the vaunted Porsche PDK. But I get that people like differing things for differing reasons or feelings.

if someone feels that coming down a mountain they "feel" more in control in disc brakes, then great! or if someone feels they are in complete control coming down a mountain in vintage campy triomphe brakes and index shifter, then great!

ride what you want guys. in my book, there is no correct choice for everyone. but there just might be a correct choice for you and the riding you do. rent the disc brake bike you are interested in (or the rim brake bike) and see what tickles your fancy. :banana:



What works best on one type of bike doesn't necessarily work best on other types of bikes. Do you also find it strange that road bikes don't have hydraulically damped suspensions, or dropper posts, or straight handlebars, or knobby tires? MTbs have them why not road bikes?

One big reason that MTBs have almost universally adopted disc brakes, is because rim brakes just don't work well on suspension forks or swingarms. Another reason is that MTBs are often used in mucky, gritty condition, which can grind down rims when rim brakes are used. Rim failures due to grinding down brake tracks was very common on MTBs when rim brakes were common, but is much less common on road bikes. I know several people who got disc brakes on the MTB simply to avoid needing to replace their rims more than once a year.

[nmrt]

Oh, BTW, I just switched to a ti disc brake road bike and sold all but one of my rim brake bike. Even I have to admit that with my 145 lb of mass, I feel that the front end of my disc brake bike feels stiffer. i feel it has to do with the additional stiffness required of a disc fork. but just because I feel the stiffness and dislike it does not mean that someone else will feel the stiffness much less dislike it.

but i do bemoan the lack of choices. many manufactures are not offering rim brake versions.

[nmrt]

Interesting. I did the same thing here in Boulder, CO.
Our Flagstaff Mountain is a 4.5 mile ride at a 9% average gradient. Coming down one day, I stopped and checked the warmth of my alloy brake tracks.

Damn...they were HOT!!

I need to learn some descending skillzzz. ;)

Like everyone else, I've heard lots of stories about overheating rims/brakes on steep descents. Then I did an experiment. Mt. Ascutney in Vermont is a 3 1/2 mile/2400 foot descent at an average grade of 12%. The road is narrow and has many switchbacks, and it is open to traffic and in a dense forrest so you can't see around corners. Needless to say, you have to use your brakes quite a bit. I descended this mountain a few times, using as much braking as necessary to remain safe, and at the bottom I immediately braked to a halt and grabbed front and rear rims to see how hot they were. They were definitely warm, but I wouldn't all them "hot". Not hot enough to worry about, anyway. I also hadn't noticed any fading of the brakes on the way down.

Maybe I'm fortunate that I'm not very heavy (I run around 150 lb), and maybe I have good descending and braking technique, but I no longer worry too much about overheating rim brakes.

[ducati2]

“I don’t visit The Paceline Forum often. But when I do, I am sure to see the same tired thread about rim vs disc brakes on bicycles”.

[Mikej]

What’s the deal with airline peanuts?

[tomato coupe]

Before COVID, I regularly rode with several present and former pro riders. Most, if not all, of them were still using rim brakes. But, they also told stories like "I destroyed a set of carbon wheels last month when they overheated descending Mt. XXX." YMMV.

[tomato coupe]

Interesting. I did the same thing here in Boulder, CO.
Our Flagstaff Mountain is a 4.5 mile ride at a 9% average gradient. Coming down one day, I stopped and checked the warmth of my alloy brake tracks.

Damn...they were HOT!!

I need to learn some descending skillzzz. ;)

It's hard to descend Flagstaff without using a lot of brake.

P.S. PDK is the schnizz.

[Frankwurst]

Isn't a canti, centerpull or sidepull essentially a disc brake? You have pads grabbing a disc going around. This is how I justify in my mind there is no reason to buy a new bike. Makes me feel better than I'm to old, fat and slow.:beer:

[XXtwindad]

“I don’t visit The Paceline Forum often. But when I do, I am sure to see the same tired thread about rim vs disc brakes on bicycles”.

This. For sure. Holy crap it gets tiresome.

[robt57]

“I don’t visit The Paceline Forum often. But when I do, I am sure to see the same tired thread about rim vs disc brakes on bicycles”.

So is this like when it doesn't rain until you wash your car. And your coming, your 'visit' caused all this? ;)

[fa63]

For me, what is so great about disc brakes is that I can use one bike in three different configurations with minimal fuss:

- 700x28c tires for road rides
- 700x42c tires for gravel rides
- 650b x 2" tires for gnarly gravel / singletrack

It takes me about a minute to recenter the pads by loosening the caliper bolts, and using the Hayes tool to reset the brakes. Works every time.

I don't see a huge benefit for the road, unless you like using carbon wheels on mountainous rides and don't want to worry about cooking your rims on the descents.

[ridethecliche]

My favorite thing about disc brakes is that all the bikes that I semi lusted after are now within reach (purchased used) just because they take rim brakes only.

Well not really... But they're certainly more affordable than the disc stuff!

[reuben]

How much of a mechanic are you?

Your post seems to be from inexperience with different brakes.

I'm not a huge mechanic. I'll mess with brakes, derailleurs, cranks, etc., but I don't get into bottom brackets.

And yes, this is my first disc brake bike.

[reuben]

I'm going to guess that you don't have multiple wheel sets for your disc brake bike

True. I don't have a need for multiple wheels for that bike.

[mcteague]

This. For sure. Holy crap it gets tiresome.

And yet, here you are...commenting. :rolleyes:

Tim

[oldpotatoe]

Every pro has a top notch bike.. unless the bike breaks or the tires are flatting it's probably never making much of a difference.

Yup, only makes a difference to the sponsors.

"more bike races have been lost due to equipment, than have been won"...

[colker]

I'd bet that the average age of people who post on this forum is quite a bit higher than the average mountain biker, and they are waaaaay less receptive to changing technology than the average mountain biker.

That´s why oldsters here don´t use cellphones, instagram, twitter, whatsup and internet forums. Nevermind the next big thing: disc brakes on road bikes.

[reuben]

That´s why oldsters here don´t use cellphones, instagram, twitter, whatsup and internet forums. Nevermind the next big thing: disc brakes on road bikes.

They don't listen to funky disco music, either. Unless it's on a cassette in their Walkman.

[benb]

I'm going to guess that you don't have multiple wheel sets for your disc brake bike, because you didn't mention one of the steps when setting up the brake - shimming the rotors. Disc brakes have very little pad clearance, which means there is a tight tolerance for variation in rotor offsets. There can be variations in rotor offset between different wheels/hubs, so to make wheels truly interchangeable the rotors often have to be shimmed. This is one of the reasons that pro racers often change bikes instead of wheels - while it is true that disc brake wheel change is only a little slower than for rim brakes, there's a good chance that the replacement wheel may have a different rotor offset (especially if the wheel is from neutral service), which can result in pad rub. While this is of vital concern for racers, it is also a bit of a hassle for anyone with multiple wheels, or who borrows wheels.

They're pro racers.. they ought to have identical wheels & rotors on the team car with everything setup.

If the wheels & rotors are so poorly made that you can't interchange identical models then it's just another reason a lot of this hyper expensive gear is kind of a joke. If shims are necessary you'd think the team mechanics would have shimmed all the spare wheels ahead of time to make sure they can keep the team running. They're at the top of the sport & they are running budgets in the millions on some of these teams. Changing wheels shouldn't be that hard.

There's a tolerance in the pads in a hydraulic caliper... the pads self adjust, if the bike industry can't set a standard & build everything within the tolerances there's bigger problems. They ought to even be able to get this right on the neutral support car.

It is kind of a joke at this point that this stuff continues to be a problem when the bikes they're riding cost as much as motorcycles & are pushing into car territory, while they are meanwhile running production stuff, not 1 off prototypes.

No different then the finger pointing when $3000 wheelsets have issues with tire beads.

[colker]

They're pro racers.. they ought to have identical wheels & rotors on the team car with everything setup.

If the wheels & rotors are so poorly made that you can't interchange identical models then it's just another reason a lot of this hyper expensive gear is kind of a joke. If shims are necessary you'd think the team mechanics would have shimmed all the spare wheels ahead of time to make sure they can keep the team running. They're at the top of the sport & they are running budgets in the millions on some of these teams. Changing wheels shouldn't be that hard.

There's a tolerance in the pads in a hydraulic caliper... the pads self adjust, if the bike industry can't set a standard & build everything within the tolerances there's bigger problems. They ought to even be able to get this right on the neutral support car.

It is kind of a joke at this point that this stuff continues to be a problem when the bikes they're riding cost as much as motorcycles & are pushing into car territory, while they are meanwhile running production stuff, not 1 off prototypes.

No different then the finger pointing when $3000 wheelsets have issues with tire beads.

I can build myself and service a rim brake road bike. If it has DT shifters it´s a breeze.
Your description of self adjusting hydraulic brakes otoh seems very complicated. I don´t care if it´s old or new but i want simple. Simple is better. Simple is happyer.

[benb]

I can build myself and service a rim brake road bike. If it has DT shifters it´s a breeze.
Your description of self adjusting hydraulic brakes otoh seems very complicated. I don´t care if it´s old or new but i want simple. Simple is better. Simple is happyer.

Self adjusting hydraulic caliper is way simpler for the user than adjusting a cable rim brake.

You put the wheel + disc into the caliper, clamp down the skewer/thru-axle.

Then you squeeze the brake lever and release it. The caliper adjusts. Every time you apply the brake it recenters. This is what has been happening successfully for 20+ years on disc equipped MTBs now. It's what motorcycles have been doing successfully for near on 50 years now. Likewise with cars.

Done.

The problem Mark was talking about has to do with hubs + rotors + calipers + mounts not being precisely made enough across the bike industry to make it work on a wheel swap. And he's right it's a real legitimate problem.

When this is a problem at the tippy top of the sport with a $1000 set of brakes + levers on a $3000 wheelset and it's all being maintained by a full time pro mechanic with a truck load of spares from the manufacturers and a direct line to a rep at the manufacturer it's not the concept of disc brakes themselves that are the issue.

I am kind of curious what kind of tolerance is actually required to make this work. It doesn't seem terribly small in the grand scheme of modern manufacturing.

Likewise when carbon wheels don't brake well with rim brakes or Carbon wheels cut tires none of that is inherently a problem with rim brakes or carbon rims or any of that. It's all just the weird dysfunctional way bike stuff gets designed and built even though it's stratospherically expensive stuff.

[Bici-Sonora]

I can build myself and service a rim brake road bike. If it has DT shifters it´s a breeze.
Your description of self adjusting hydraulic brakes otoh seems very complicated. I don´t care if it´s old or new but i want simple. Simple is better. Simple is happyer.


Plus 1 on this ^^^. More complication for marginal gains is a no-go for me. Clean, simple, quiet, and uncluttered are what I want in a road bike. Also, serviceability with tools I already own. Rim brakes on my road bikes achieve those goals better than discs IME.

In that same spirit, if I could buy Record or DA 11 and/or 12 speed DT shifters—all my bikes would have them.


Sent from my iPhone using Tapatalk

[colker]

Self adjusting hydraulic caliper is way simpler for the user than adjusting a cable rim brake.

.

Cantis can be a pita. Vees on the dirt can eat the rims.. but sidepulls? The most simple part to adjust on a bike. Easier than tightening a stem bolt.

[chirpy999]

Disks are self adjusting, its progress. Embrace it .

[colker]

Disks are self adjusting, its progress. Embrace it .

Progress is the worst argument ever.

[Waldo62]

Are you describing disc brakes, or the people who complain about them?

No, the people who use them.

[Kirk007]

Disks are self adjusting, its progress. Embrace it .

I'm tired of "embracing" having to adjust the calipers with every wheel change and dealing with slightly out of true rotors on the etap direct mount brakes that I have. Maybe I'll try one of those Hayes tools. The Industry has a ways to go before dealing with road hydro brakes are as stupid simple to adjust as a modern rim brake and the phrase "progress" can be applied to this aspect of disc brakes.

[hellvetica]

Disc brakes are great. On my mountain bikes.

[benb]

Oh well, we've been having this discussion on road disc for 10 years or so now, only another 10 years till the industry gets its act together.

All part of the plan to get us to buy 5 bikes that don't work right with the hope that they work right and then finally sell us the 6th one that works.

Right after that they'll invent some new type of brake and tell us discs are obsolete and it'll take 20 years of customer beta testing to get that to work right.

[oldpotatoe]

I'm tired of "embracing" having to adjust the calipers with every wheel change and dealing with slightly out of true rotors on the etap direct mount brakes that I have. Maybe I'll try one of those Hayes tools. The Industry has a ways to go before dealing with road hydro brakes are as stupid simple to adjust as a modern rim brake and the phrase "progress" can be applied to this aspect of disc brakes.

PLus
if the bike industry can't set a standard & build everything within the tolerances there's bigger problems.

'Standardized' and 'bike industry' are oxymorons

[OtayBW]

Disks are self-embracing. Adjust it. It's progress.

[mcteague]

Might as well throw some fuel on these smouldering embers.

https://www.cyclingnews.com/news/giro-dellemilia-pellaud-left-with-facial-injuries-following-brake-failure/

Giro dell'Emilia: Pellaud left with facial injuries after brake failure

Swiss rider explains that disc brakes failed on descent

Tim

[oldpotatoe]

Might as well throw some fuel on these smouldering embers.

https://www.cyclingnews.com/news/giro-dellemilia-pellaud-left-with-facial-injuries-following-brake-failure/

Giro dell'Emilia: Pellaud left with facial injuries after brake failure

Swiss rider explains that disc brakes failed on descent

Tim

Brake fad is a BIG problem on the uber beefy set ups on cars and trucks..no reason to think the teeny, poorly ventilated, teeny amount of fluid, road disc brakes wouldn't do the same thing..

[vespasianus]

Brake fad is a BIG problem on the uber beefy set ups on cars and trucks..no reason to think the teeny, poorly ventilated, teeny amount of fluid, road disc brakes wouldn't do the same thing..


I would argue that brake fade was an issue in the MTB space but for the most part, has been solved with larger rotors and better design. DOT fluid is also supposed to do better, which is way Hayes and SRAM say they use it.

I do see lots of bigger people using 140mm rotors (front and rear), which I think could cause "normal people" problems. I laud Campagnolo for highly recommending 160mm rotors front and back for larger riders.

What is interesting is that pro who crashed had both front and rear systems fail. That is sounds like a service issue to me.

[Red Tornado]

disc brakes are great. On my mountain bikes.

+1

[Mark McM]

I would argue that brake fade was an issue in the MTB space but for the most part, has been solved with larger rotors and better design. DOT fluid is also supposed to do better, which is way Hayes and SRAM say they use it.

I do see lots of bigger people using 140mm rotors (front and rear), which I think could cause "normal people" problems. I laud Campagnolo for highly recommending 160mm rotors front and back for larger riders.

Motorcycles, which have a least a little similarity to bicycles, have used disc brakes far longer than bicycles. It is almost universal that road motorcycles have bigger rotors than off-road motorcycles. Based on the laws of physics, this makes sense - road motorcycles often go much faster than off-road motorcycles, and braking at high speeds generates far more heat than braking at lower speeds (for example, braking from 60mph to 50mph generates over twice the heat as braking from 30 mph to 20 mph). Then why do so many people think that road bikes should have smaller discs than MTBs? The bicycle designers likely know this, but as in so many other cases, they create products that users think they want, rather than products that make sense.

[Tony]

Motorcycles, which have a least a little similarity to bicycles, have used disc brakes far longer than bicycles. It is almost universal that road motorcycles have bigger rotors than off-road motorcycles. Based on the laws of physics, this makes sense - road motorcycles often go much faster than off-road motorcycles, and braking at high speeds generates far more heat than braking at lower speeds (for example, braking from 60mph to 50mph generates over twice the heat as braking from 30 mph to 20 mph). Then why do so many people think that road bikes should have smaller discs than MTBs? The bicycle designers likely know this, but as in so many other cases, they create products that users think they want, rather than products that make sense.

Weight also plays a big roll in why road motorcycles have bigger rotors than off-road motorcycles. A road bike can weight 3-4 times more than a dirt bike.

Also why mtb have bigger rotors, weight and speed.

[benb]

Road bikes barely every use their brakes so that might be part of it. Easy to be complacent since most rides you're probably barely using 10% of the capability of a rim brake.

But common sense and engineering dictate you design the brake system to cover the most severe situation the bike encounters not the average or light duty scenario.

A high speed mountain road descent with hairpins that you have to brake hard for is the hardest thing I've seen.

MTBs & Motorcycles get it. MTBs are overbuilt like motorcycles.

Most sporting motorcycles IME are ready to go at the track right out of the box. They are massively over braked for the road. There's no situation on the road where you're constantly braking from 125-150mph down to 30-60mph for the corners and repeating that every few seconds. I never got a hint of fade at the track on any moto I owned.

My experience with my MTBs & discs is that the disc brakes that I picked out at least are plenty overbuilt that I have nothing to worry about. I bought a trail type setup (DOT) instead of an XC type setup that would be more inline with my bike. My setup has massive piles of reserve power & fade resistance. My MTB can easily descend any paved mountain descent I've ever experienced and can safely stop the bike even if one of the two brakes failed, even if that was the front brake where most of the power resides. On dirt the only way I'd ever stress it was going to a ski area. I have no interest in lift serviced riding but I have done an up-down at a ski area where I just rode up to the top of the mountain and then came back down the ski trails. That did test the brakes a little but never in a way that fade was a concern.

A lot of the nastiest road descents I've rode (New England) fade road rim brakes very easily and if the front brake failed you would not be able to stop the bike most likely. I would say the motorcycles I owned might have been in the same scenario... on a 15-20% descent with a hairpin if the front brake failed the rear might not be sufficient to safely stop.

But I know my MTB can actually stop on just the rear brake on such a 15-20% slope like that cause I've tried it.

These pro teams should be specifying a system that can at least handle a partial failure IMO instead of worrying about weight weenie factors.

15-20% slopes are rare in road riding anyway...

But the only road Disc systems I've test rode were the TRP Spyre and the Shimano Ultegra Ui2 hydraulic setup... honestly not sure I really thought either of those setups were really meaningfully stronger than rim brakes.. they didn't really seem strong enough for the worse case scenario, but they were test rides so I really don't know. But even that Ultegra setup was not that confidence inspiring IMO relative to what I expect from a MTB or Motorcycle. It's partly why I still stuck with rim brakes on my Trek Domane. The disc systems in 2016 didn't seem good enough to bother.

[Mark McM]

Weight also plays a big roll in why road motorcycles have bigger rotors than off-road motorcycles. A road bike can weight 3-4 times more than a dirt bike.

Also why mtb have bigger rotors, weight and speed.

Yes, road motorcycles are often heavier than off-road motorcycles, but that only partially explains why road motorcycles have larger rotors. However, the system weight of an MTB + rider is nearly the same as a a road bicycle + rider, so by mass alone they should have the same size rotors. And then when you throw in the greater speed of road bicycles, road bicycles should have bigger rotors.

[Tony]

Yes, road motorcycles are often heavier than off-road motorcycles, but that only partially explains why road motorcycles have larger rotors. However, the system weight of an MTB + rider is nearly the same as a a road bicycle + rider, so by mass alone they should have the same size rotors. And then when you throw in the greater speed of road bicycles, road bicycles should have bigger rotors.

Mtb brake usage is far greater than road usage, bombing downhill, environmental conditions, on and off the brakes, much different than road.

[Mark McM]

Mtb brake usage is far greater than road usage, bombing downhill, environmental conditions, on and off the brakes, much different than road.

You don't design brakes (or any other safety equipment) around average usage, you base it around worst case. For example, I wear out my MTB brakes much faster than my road brakes - but in worst case situations, I heat up my road brakes far more than I heat up my MTB brakes.

[David Tollefson]

Most sporting motorcycles ... There's no situation on the road where you're constantly braking from 125-150mph down to 30-60mph for the corners and repeating that every few seconds.

But on the road you're also not heading for the pits after 20 minutes for a full check-up.

[benb]

But on the road you're also not heading for the pits after 20 minutes for a full check-up.

True but most street bikes will do session after session and barely wear the pads at all. You can do a couple track days a year and not even notice any accelerated wear on anything.

It's a total non-issue until actual racing is happening.. and even then the first mods seem to be safety related and not performance related. (e.x. safety wiring)

[BdaGhisallo]

I would argue that brake fade was an issue in the MTB space but for the most part, has been solved with larger rotors and better design. DOT fluid is also supposed to do better, which is way Hayes and SRAM say they use it.

I do see lots of bigger people using 140mm rotors (front and rear), which I think could cause "normal people" problems. I laud Campagnolo for highly recommending 160mm rotors front and back for larger riders.

What is interesting is that pro who crashed had both front and rear systems fail. That is sounds like a service issue to me.


It looks like Mathieu van der Poel is one of those folks using 140 rotors front and rear. This was taken at the Tour of Lombardy:

[benb]

FWIW he saves 18g by going with a 140 in front instead of a 160 with current Dura-Ace.

Not sure why a team would ever do that.

Seems like the last place to try and save 18g.

[tuscanyswe]

FWIW he saves 18g by going with a 140 in front instead of a 160 with current Dura-Ace.

Not sure why a team would ever do that.

Seems like the last place to try and save 18g.

Does that include the brake adapters or only the rotor weight? :)

Its the loss of aeroness ::banana::

[benb]

You lose so much aero when you crash on a descent unfortunately.

You probably lose some weight off both the bike and rider though. :banana:

For 18g they should have someone sand the water bottles and drillium the bar tape or something instead of taking it off the rotors.

That's about the mass of the beans I put in a 350ml coffee, or 9 of my V60 paper filters.

[oldpotatoe]

These pro teams should be specifying a system that can at least handle a partial failure IMO instead of worrying about weight weenie factors.


The teams aren't worrying about 'weight weenie factors', the sponsors are. AND why 'some' pros still opt for rim brakes..weight, complexity, wheel changes, etc..safety...

[mcteague]

Nice write-up on an English with "integrated disk rotors"! :D

https://cyclingtips.com/2020/08/bikes-of-the-bunch-rob-englishs-english-road-bike/

Road disc brakes are pretty great, in terms of stopping power, modulation and consistency. However, the very tight tolerances between pads and disc can be frustrating to set up without rub, and it only takes a slight ding to the rotor to have a constant noise that can be tricky to remedy.

So, a thought experiment. Why are the pads so close to the rotor? In order to get the most mechanical leverage – a big movement at the lever equals a small movement at the pads. But why do we need that much leverage? Because the rotors are very small, so to be able to slow the much larger rotating mass of the wheel, we have to squeeze the rotor tightly. Therefore if the rotor was bigger, we could have a caliper with the pads further away, and this would be fine as we wouldn’t need as much mechanical advantage.

To take this to the extreme example, what if the rotor was the size of the rim? Like 622 mm in diameter. In looking at this problem, it became apparent that it would be possible to dispense with a separate rotor and use the rim of the wheel as the braking surface. Testing of different materials for the braking surface and the pads concluded that a machined aluminium surface and standard pads provides fantastic dry weather braking. They’re not awesome in the wet — for those conditions having the braking surface further away from the wet tire/rim in the form of a separate, smaller rotor makes the best sense.


Tim

[54ny77]

You can slice deli meats with it.

[J.Higgins]

Disc brakes are excellent for endless debate on cycling forums

There are no options for liking other members' posts here on this forum, so here you go.

:beer:

[vespasianus]

It looks like Mathieu van der Poel is one of those folks using 140 rotors front and rear. This was taken at the Tour of Lombardy:

And at 165 lbs, he can and should. I am talking about some guys that are 220-230.


ps. I don't consider van der Poel normal either! (:

[benb]

And at 165 lbs, he can and should. I am talking about some guys that are 220-230.


ps. I don't consider van der Poel normal either! (:

The idea that 165lbs is fine with 140mm rotors and some other higher weight needs 160s though.. what is the basis for that?

It seems like it's typical bike shop wisdom and probably not based on any empirical evidence based on testing.

I would be curious what the swept area is on the 2 discs, how much faster the 160mm rotor sheds heat, etc..

I think a little more or less weight on the rider is probably not as big a factor as the amount of speed involved. I'm not 100% sure but I think you look at this in terms of kinetic energy being converted to heat and if you look at it that way the riders speed (read the terrain you're descending) is far more important.

I'd be curious whether this kind of engineering even went into the brakes.. it clearly probably never went into the design of rim brakes considering how easy they overheat in the mountains and that they were probably designed before anyone would have been thinking of trying to model or measure it.

All IME... but I've never had a set of rim road brakes which didn't overheat massively on our summit road descents in the northeast.. they're overheating and faded within 1/2 mile even with very judicious use of the brakes. No secret why almost all of our hill climb races have long banned road bikes descending back down the roads after the race to the top, which is a huge PITA because it creates a massive logistical mess because they require every rider to go back down the road in a car since the cars are more capable of staying in control!

Most of what I've seen in Europe is more carefully engineered and maintained roads so I can see it being less of an issue in the big races there. Here we just don't have road surfaces that are OK for a road bike to be run out to 50mph and then slam on the brakes before a hair pin turn, the road surface is too rough to carry speed like that on skinny tires.

[vespasianus]

Yes, road motorcycles are often heavier than off-road motorcycles, but that only partially explains why road motorcycles have larger rotors. However, the system weight of an MTB + rider is nearly the same as a a road bicycle + rider, so by mass alone they should have the same size rotors. And then when you throw in the greater speed of road bicycles, road bicycles should have bigger rotors.

My carbon framed IBIS is ~30lbs and I am getting away with 180mm rotors. My carbon road bike is 15.84. I use my brakes a TON more on the MTB as compared to the road bike. And it is generally harder braking.

With that said, I think 160 rotors should work for most road cyclists with a 140 options for light riders.

[benb]

I think the other thing unsaid here is pad material...

The organic pads a lot of road systems seem to be defaulted to are not the wisest choice for these torture test scenarios where you're descending a big mountain road with high speeds and the need to repeatedly brake hard for twists in the road.

If you consider that case the road systems seem to default to:
- Mineral oil - boils easier
- Organic pads - cook easier
- Smaller rotors - dissipate less heat

The weight of a MTB vs the weight of the road bike are not a big deal IMO versus the weight of the rider and the velocities involved.

I use the brakes more on my MTB for sure if you measure the # of times I touch the brake lever within a certain period of time.

But I definitely never need to hold the brakes for as extended of a period on my MTB as I would on a road bike descending a road that averages 10% or greater.

I have 180mm rotors with DOT fluid on my MTB w/sintered metallic pads right now.. most of the time my brake actuations on the MTB are less than 1 second as the bike sheds the speed incredibly quickly.

On a road bike particularly with the rim brakes if you're at 40mph and you need to slow to 10-15 to take a really hard corner it takes a lot longer than 1-2 seconds to shed that speed.. you're holding the brakes longer and building up heat faster. Realistically those big mountain descents I find myself very quickly having to apply a rim brake for long periods of time even trying really hard to let the bike run to cool the rims.

If I spend the money on road disc I want it to perform like my MTB... great modulation, and zero concern about ever overheating on any mountain road or ever needing more than a brief 1-finger pull to shed off any amount of speed, with enough reserve that I can safely stop/descend that road even if one of the 2 brakes completely fails. I want the rotor size, pad material, and fluid all specified for the absolute most demanding & dangerous situation I could ever find myself in.

[Tony]

I think the other thing unsaid here is pad material...

The organic pads a lot of road systems seem to be defaulted to are not the wisest choice for these torture test scenarios where you're descending a big mountain road with high speeds and the need to repeatedly brake hard for twists in the road.

If you consider that case the road systems seem to default to:
- Mineral oil - boils easier
- Organic pads - cook easier
- Smaller rotors - dissipate less heat

The weight of a MTB vs the weight of the road bike are not a big deal IMO versus the weight of the rider and the velocities involved.

I use the brakes more on my MTB for sure if you measure the # of times I touch the brake lever within a certain period of time.

But I definitely never need to hold the brakes for as extended of a period on my MTB as I would on a road bike descending a road that averages 10% or greater.

I have 180mm rotors with DOT fluid on my MTB w/sintered metallic pads right now.. most of the time my brake actuations on the MTB are less than 1 second as the bike sheds the speed incredibly quickly.

On a road bike particularly with the rim brakes if you're at 40mph and you need to slow to 10-15 to take a really hard corner it takes a lot longer than 1-2 seconds to shed that speed.. you're holding the brakes longer and building up heat faster. Realistically those big mountain descents I find myself very quickly having to apply a rim brake for long periods of time even trying really hard to let the bike run to cool the rims.

If I spend the money on road disc I want it to perform like my MTB... great modulation, and zero concern about ever overheating on any mountain road or ever needing more than a brief 1-finger pull to shed off any amount of speed, with enough reserve that I can safely stop/descend that road even if one of the 2 brakes completely fails. I want the rotor size, pad material, and fluid all specified for the absolute most demanding & dangerous situation I could ever find myself in.

The Suzuki sv650 brakes are a weak point. Switching to sintered pads and stainless steel lines was one of the best bang for buck upgrade, big improvement, specially up front!

[Mark McM]

All IME... but I've never had a set of rim road brakes which didn't overheat massively on our summit road descents in the northeast.. they're overheating and faded within 1/2 mile even with very judicious use of the brakes. No secret why almost all of our hill climb races have long banned road bikes descending back down the roads after the race to the top, which is a huge PITA because it creates a massive logistical mess because they require every rider to go back down the road in a car since the cars are more capable of staying in control!

The only two hill climb race in the northeast I am aware of that don't allow bikes to ride back down Mt. Washington and Mt. Equinox, but that's mostly because they are on private roads that don't generally allow bicycles on the roads at all. (The prohibition for bicycles on Mt. Washington is probably illegal, according to cycling attorney Bob Mionske). The Burke Mountain, Mt. Ascutney, and Mt. Mansfield summit roads are just as steep as Equinox and Washington, and don't prohibit bicycles (up or down).

[Mark McM]

My carbon framed IBIS is ~30lbs and I am getting away with 180mm rotors. My carbon road bike is 15.84. I use my brakes a TON more on the MTB as compared to the road bike. And it is generally harder braking.

It's not the weight of the bike that matters, it is the total weight of the bike + rider. The total weight of MTB + rider is only a few percent more than for road bike + rider.

While you may very well brake more often on the MTB, it probably isn't harder than on a road bike, for two reasons: Road bikes typically go faster than MTBs, and braking heat is proportional to speed (i.e. for the same braking force, the heat generated by braking at 40 mph is twice the the heat generated when braking at 20 mph); and the greater traction on asphalt means that you can brake much harder on a road bike (which means generating heat faster).

Riding off road can be harder that on road in many ways, but generating brake heat isn't one of them.

[AngryScientist]

On a road bike particularly with the rim brakes if you're at 40mph and you need to slow to 10-15 to take a really hard corner it takes a lot longer than 1-2 seconds to shed that speed.. you're holding the brakes longer and building up heat faster. Realistically those big mountain descents I find myself very quickly having to apply a rim brake for long periods of time even trying really hard to let the bike run to cool the rims.

.

just curious: how much do you weigh ben?

my experience with rim brake bicycles in the northeast does not match yours, not even close.

[Tony]

just curious: how much do you weigh ben?

my experience with rim brake bicycles in the northeast does not match yours, not even close.

If one is holding to 40 mph on a long descent I can see the problem/concern.

Where my experience does not match is the time to slow from 40 to 10-15 mph. 40 mph is not that fast, dropping from 40 to 10-15 mph for a sharp corner is just two fingers and at the most 3-4 seconds away with my rim brakes?